SLIP and SerialIP

Hi, I've been trying to connect to the internet from my Arduino via SLIP and the SerialIP library. I am using Windows XP and I followed the PDF file that was linked in the wiki. However, even though I'm using the HelloWorldExample I get a 777 error when attempting to connect to the Arduino from XP. I've followed the guide exactly (right down to names although I know this SHOULDN'T affect it)